A principal component of the wound healing process is the restoration of structural and functional integrity to the injured tissue. This involves the extensive biosynthesis, deposition and remodelling of collagen within the wound area. Previous investigations into collagen metabolism in tissue repair have dealt primarily with collagen biosynthesis and deposition alone. Consequently, the physiological role of collagenase in wound healing is mostly speculative. The overall objective of this study is to examine collagenase in tissue repair. This will encompass the determination of enzyme activity, enzyme distribution and the cell source of this enzyme during wound healing. Collagenase isolated and purified from rat dermal fibroblasts, macrophages and granulocytes will be biochemically characterized. In particular, the ability of each collagenase to degrade different collagen types will be examined. The collagenase activity, in these preparations and in tissue samples, will be quantitated using a recently developed collagenase assay which possesses high sensitivity. The purified collagenases will be used to produce highly specific monoclonal antibodies through hybridoma technology. These antibodies will be employed to immunohistochemically localize each type of collagenase in tissue sections from an in vivo wound model. With the monoclonal antibodies directed against collagenases from different sources, and the collagenase assay, the started objectives of the study should be achieved. The modulation of extracellular collagenase activity by the serum inhibitor alpha-2-macro-globulin will be studied to determine the physiological relevance of this interaction. These studies are essential to the understanding of normal wound healing, with the proposed experiments examing the in vivo relationship of collangease to this basic physiological process. With this information, it will be possible to examine such disorders as hypertorphic burn scars, keloids and ulcers, which may result from alterations in normal collagenase regulation. In addition, the clinically apparent effects of steroids on wound healing may be produced by a pharmacological interaction of these compounds on collagenase regulation. These studies are all dependent on the information derived from this proposed investigation.